Weld-Induced Residual Stress Evolution in 347H Stainless Steel Large Tanks

Weldability issues often arise from a combination of three factors: tensile residual stresses, susceptible microstructures, and severe service environments, which can lead to premature failures. For instance, stress relaxation cracking, also known as reheat cracking, remains a critical concern in weldments of precipitation strengthened stainless steels (e.g., 347H) for industries such as molten salt storage and petrochemicals in pressurized or highly constrained components operating above 500°C. Residual stress plays a particularly vital role in the stress relaxation cracking mechanism. This study employs an approach combining neutron diffraction and finite element modeling to achieve a comprehensive understanding of stress evolution during welding, post weld heat treatment, service and repair processes in 347H stainless steel large storage tanks to develop effective stress mitigation strategies, ultimately enhancing the service life of welded 347H stainless steel components.